Up to this point the video demos coming out of Canonical of Mir have been Unity-Next running on mobile devices. Jono Bacon, the Ubuntu Community Manager, has now posted a video showing off the next-generation Unity interface being powered by the Mir Display Server running on a Retina MacBook Pro.
Jono commented on the video, "This demo is running on a MacBook Pro Retina utilizing the full resolution of 2880x1800 pixels and using Intel HD 4400 graphics. The performance is already looking great, and the team haven't done a deep dive into performance optimization yet."
Embedded below is this new Mir demo.